From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAB0CC77B73 for ; Mon, 8 May 2023 10:23:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234548AbjEHKXO (ORCPT ); Mon, 8 May 2023 06:23:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234524AbjEHKW3 (ORCPT ); Mon, 8 May 2023 06:22:29 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A289ED85D for ; Mon, 8 May 2023 03:22:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2AF0F62537 for ; Mon, 8 May 2023 10:22:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FAEAC433D2; Mon, 8 May 2023 10:21:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683541319; bh=Dn7/AtU8ESNkh3jYjBIKfJ+iDq7Jl5vSm61UxFUFu5E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0Cffz6XRPAPOB0OsfusyW9fiHZB7c4mbRRBr80e3Ts/8cY5AMZXSna2lH5VsNBwnm ok7VfVNfT60s9uEqyVZFkuH1Yo/wYW9Zils75cDI08xHIQwQHt4779tuHwGXJ+/az4 3wIxxNxQafXcw+H/Ag3xg6QquhUx8IzCp/S/960Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yang Weijiang , Like Xu , Paolo Bonzini , Like Xu , Sean Christopherson Subject: [PATCH 6.2 077/663] KVM: x86/pmu: Disallow legacy LBRs if architectural LBRs are available Date: Mon, 8 May 2023 11:38:23 +0200 Message-Id: <20230508094430.953849065@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094428.384831245@linuxfoundation.org> References: <20230508094428.384831245@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sean Christopherson commit 098f4c061ea10b777033b71c10bd9fd706820ee9 upstream. Disallow enabling LBR support if the CPU supports architectural LBRs. Traditional LBR support is absent on CPU models that have architectural LBRs, and KVM doesn't yet support arch LBRs, i.e. KVM will pass through non-existent MSRs if userspace enables LBRs for the guest. Cc: stable@vger.kernel.org Cc: Yang Weijiang Cc: Like Xu Reported-by: Paolo Bonzini Fixes: be635e34c284 ("KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES") Tested-by: Like Xu Link: https://lore.kernel.org/r/20230128001427.2548858-1-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx/vmx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7749,9 +7749,11 @@ static u64 vmx_get_perf_capabilities(voi if (boot_cpu_has(X86_FEATURE_PDCM)) rdmsrl(MSR_IA32_PERF_CAPABILITIES, host_perf_cap); - x86_perf_get_lbr(&lbr); - if (lbr.nr) - perf_cap |= host_perf_cap & PMU_CAP_LBR_FMT; + if (!cpu_feature_enabled(X86_FEATURE_ARCH_LBR)) { + x86_perf_get_lbr(&lbr); + if (lbr.nr) + perf_cap |= host_perf_cap & PMU_CAP_LBR_FMT; + } if (vmx_pebs_supported()) { perf_cap |= host_perf_cap & PERF_CAP_PEBS_MASK;